3-Phenoxybenzyl compounds

ABSTRACT

The invention relates to 3-phenoxybenzyl compounds of the formula ##STR1## wherein R 1  is hydrogen, cyano, --CSNH 2 , C 2  -C 3  alkenyl or C 2  -C 3  alkynyl and R 2  is alkenyl or alkynyl, as intermediates for the production of biocides. 
     The preparation of the 3-phenoxybenzaldehydes employed as intermediates is described. Novel 3-phenoxybenzaldehydes used as starting materials and the production thereof are also disclosed.

The present invention relates to 3-phenoxybenzyl compounds, to theproduction thereof and to the use thereof as intermediates for thesynthesis of biocides.

The 3-phenoxybenzyl compounds of the invention have the formula ##STR2##wherein R₁ is hydrogen, cyano, --CSNH₂, allenyl, C₂ -C₃ alkenyl or C₂-C₃ alkynyl, and R₂ is alkenyl or alkynyl.

Alkenyl or alkynyl groups suitable for R₂ may be straight chain orbranched, unsubstituted or substituted, and the double or triple bond isconjugated with the phenyl nucleus. Alkenyl and alkynyl groups R₂contain preferably 2 to 6, especially 2 to 3, carbon atoms.

Examples of preferred substituents carried by these groups are: cyano,halogen such as fluorine, chlorine, bromine or iodine, with bromine oriodine being preferred, and C₁ -C₆ alkyl, C₁ -C₆ hydroxyalkyl, C₁ -C₆haloalkyl or dimethylamino.

Interesting intermediates are compounds of formula I, wherein R₁ ishydrogen, cyano, allenyl or ethynyl, and R₂ is p-vinyl, p-1-propenyl,p-3-dimethylamino-1-propenyl, p-ethynyl, p-1-propynyl, p-iodoethynyl orp-3-dimethylamino-1-propynyl.

Particularly interesting intermediates, however, are compounds offormula I, wherein R₁ is hydrogen or cyano, and R₂ is p-vinyl,p-1-propenyl, p-ethynyl or p-1-propynyl.

The compounds of formula I can be obtained by methods which are knownper se, e.g. as follows: ##STR3## R₂ in formula II is as defined forformula I.

The processes are carried out at a reaction temperature in the rangefrom -10° to 100° C., with the preferred range being from 0° to 80° C.,in general under normal pressure and, if desired, in an inert solvent ordiluent. Suitable solvents or diluents are, in particular, ethers suchas diethyl ether, tetrahydrofurane or dioxane for the second process,whereas it is preferred to use an alcohol such as methanol or ethanolfor processes 1 and 3.

The compounds of formula II, which can be obtained by methods which areknown per se, are novel and likewise constitute an object of the presentinvention.

The compounds of formula I are suitable for use as intermediates for theproduction of e.g. pyrethroids (cf. Example 2), which are suitable forcontrolling insects of the family Arthropoda, such as of the classesinsecta and Arachnoida.

EXAMPLE 1: Preparation of m-(p-ethynylphenoxy)benzyl alcohols ##STR4##

(a) A mixture of 33.5 g of the compound of formula III, 13.1 g of2-methyl-3-butin-2-ol, 104 ml of triethylamine, 0.73 g of (Ph₃ P)₂ PdCl₂and 0.4 g of CuI is heated to 80° C. The mixture is stirred for 16 hoursat 80° C., filtered, and the filtrate is extracted with ether. Theethereal phase is washed with ammonium chloride and then with sodiumchloride solution, dried over magnesium sulfate and concentrated.

The crude product is chromatographed over silica gel with ether/hexane(1:1) as eluant, to give the compound of the formula IV with arefractive index of n_(D) ²⁰° =1.5445.

(b) A mixture of 50 g of the compound of formula IV, 5 g of KOH and 50 gof K₂ CO₃ in 500 ml of toluene is heated to 140° C. The toluene isdistilled off and the residue is chromatographed over silica gel withhexane/ether (10:1) as eluant, to give the compound of the formula Vwith a refractive index of n_(D) ²⁰° =1.5748.

(c) 17.9 g of the compound of formula V, 67 ml of 2 N HCl and 33.5 ml ofglacial acetic acid are stirred for 2 hours at 60° C. The reactionmixture is poured into sodium acetate and extracted with ethyl acetate.The ethyl acetate phase is washed twice with sodium acetate and oncewith saturated sodium chloride solution, dried over magnesium sulfateand dried. The crude product is chromatographed over silica gel withhexane/ether (5:1) as eluant, to give the compound of the formula VIwith a refractive index of n_(D) ²⁰° =1.6009.

(d) 0.18 g of NaBH₄ and 1.4 ml of water are put into a reactor undernitrogen. With cooling, 3.5 g of the aldehyde of formula VI in 11.4 mlof methanol are slowly added dropwise. The reaction mixture is stirredfor 12 hours at 20° C., then diluted with water and extracted twice withCH₂ Cl. The organic phase is washed with saturated sodium chloridesolution and dried over magnesium sulfate. The crude product ischromatographed over silica gel with hexane/ether (1:1) as eluant,affording the compound of the formula VII with a refractive index ofn_(D) ²⁰° =1.5942.

(e) To 3.3 g of sodium cyanide in 4 ml of water and 87 ml of methanolare added dropwise, at 0° C., first 10 g of the aldehyde of the formulaVI ##STR5## in 10 ml of methanol and then 10.3 ml of acetic acid. Thereaction mixture is stirred for 2 hours at 20° C., then poured into icedwater and extracted with CH₂ Cl. The organic phase is extracted oncewith sodium acetate and twice with iced water, dried over magnesiumsulfate, filtered and concentrated, affording the desired α-cyanobenzylalchol (formula VIII) with a refractive index of n_(D) ²⁰° =1.6049.

(f) Hydrogen is introduced at 20° C. into a solution of 10 g of thecompound of formula V in 100 ml of dimethyl formamide with 1 g ofLindlar catalyst. After the uptake of 1 equivalent of hydrogen, thereaction mixture is filtered and the solvent is removed under reducedpressure, affording the compound of the formula XI with a refractiveindex of n_(D) ²⁰° =1.5828.

The compound of the formula X with a refractive index of n_(D) ³⁰°=1.6128 is obtained from the compound of formula IX by a proceduresimilar to that of step (c). The compound of the formula XI with arefractive index of n_(D) ³⁰° =1.6061 is obtained from the aldehyde offormula X in a manner similar to that of step (e). The compound of theformula XII with a refractive index of n_(D) ³⁰° =1.5963 is obtainedfrom the compound of formula XI in a manner similar to that of step (e).

The following compounds are also prepared in similar manner and by knownmethods.

    ______________________________________                                         ##STR6##                                                                     R'               R"           Physical data                                   ______________________________________                                        CH.sub.3CC                                                                                      ##STR7##    n.sub.D.sup.20°  = 1.5911                CH.sub.3CC       CHO          n.sub.D.sup.30°  =                                                     1.6212                                          CH.sub.3CC                                                                                      ##STR8##    n.sub.D.sup.20°  = 1.6071                CH.sub.3CC                                                                                      ##STR9##    n.sub.D.sup.20°  = 1.6159                CH.sub.3CC                                                                                      ##STR10##   n.sub.D.sup.20°  = 1.6128                CH.sub.3CHCH     CH.sub.2 OH  n.sub.D.sup.20°  =                                                     1.6057                                          CH.sub.3CHCH                                                                                    ##STR11##   n.sub.D.sup.20°  = 1.5790                CH.sub.3CHCH     CHO          n.sub.D.sup.20 °  =                                                    1.640                                           CH.sub.3CHCH                                                                                    ##STR12##   n.sub.D.sup.20°  = 1.6094                ICC                                                                                             ##STR13##   m.p.: 72-74° C.                          ICC              CHO          m.p.:                                                                         106-111° C.                              ICC                                                                                             ##STR14##   n.sub.D.sup.20°  = 1.6013                (CH.sub.3).sub.2 NCH.sub.2CHCH                                                                 CHO          n.sub.D.sup.20°  =                                                     1.5922                                          (CH.sub.3).sub.2 NCH.sub.2CHCH                                                                  ##STR15##   n.sub.D.sup.20°  = 1.5687                (CH.sub.3).sub.2 NCH.sub.2CC                                                                   CHO          n.sub.D.sup.20°  =                                                     1.6018                                          (CH.sub.3).sub.2 NCH.sub.2CC                                                                    ##STR16##   n.sub.D.sup.20°  = 1.6220                ______________________________________                                    

EXAMPLE 2: Preparation of the biocide of the formula ##STR17##

To a solution of 2.3 g of the compound of the formula ##STR18## in 20 mlof toluene are added dropwise, at 0° C., first 1 ml of pyridine and thena solution of 5.4 g of the compound of the formula ##STR19## in 20 ml oftoluene.

The reaction mixture is stirred for 12 hours at 20° C., then poured into2 N hydrochloric acid, extracted once with 10% potassium carbonatesolution, once with saturated sodium carbonate solution and once withsaturated sodium chloride solution. The extracts are dried overmagnesium sulfate, filtered and concentrated. The crude product ischromatographed over silica gel with toluene as eluant, affording thecompound of the formula XIII with a refractive index of n_(D) ²⁰°=1.5811.

What is claimed is:
 1. A 3-phenoxybenzyl alcohol of the formula##STR20## wherein R₁ is hydrogen, cyano, --CSNH₂, allenyl, C₂ -C₃alkenyl or C₂ -C₃ alkynyl, and R₂ is alkenyl or alkynyl.
 2. A compoundaccording to claim 1, wherein R₁ is hydrogen, cyano, allenyl or ethynyl,and R₂ is p-vinyl, p-1-propenyl, p-3-dimethylamino-1-propenyl,p-ethynyl, p-1-propynyl, p-iodoethynyl or p-3-dimethylamino-1-propynyl.3. A compound according to claim 2, wherein R₁ is hydrogen or cyano, R₂is p-vinyl, p-1-propenyl, p-ethynyl or p-1-propynyl, and X₁ is hydroxyl.4. The compound according to claim 3 of the formula ##STR21##
 5. Thecompound according to claim 3 of the formula ##STR22##
 6. The compoundaccording to claim 3 of the formula ##STR23##
 7. The compound accordingto claim 2 of the formula ##STR24##
 8. The compound according to claim 2of the formula ##STR25##
 9. The compound according to claim 2 of theformula ##STR26##
 10. A 3-phenoxybenzaldehyde of the formula ##STR27##wherein R₂ is as defined in claim 1.